1. Field of the Invention
The present invention relates to N-tetrazolyl thiazolecarboxamide derivatives having antiallergic activity, a process for preparation thereof and a pharmaceutical composition comprising the said derivatives.
Various compounds including disodium cromoglicate, chlorpheniramine maleate, tranilast etc. have been known to have the antiallergic activity and practically used on the basis of such activity. However, they have a number of deficiencies such as induction of undesirable side effects, insufficiency of peroral absorption and unsatisfactoriness of therapeutic effect. Accordingly, there has been a continuous demand for antiallergic agent which has not such deficiencies.
After an extensive study on the antiallergic agents, the present inventors have discovered that a certain group of N-tetrazolyl thiazolecarboxamide derivatives have an excellent antiallergic activity even if they administered perorally and have less side effects.
2. Related Disclosures
N-substituted phenylthiazolecarboxamide derivates wherein the substituents are alkyl, aryl, alicyclic or benzyl are disclosed in Japanese Patent Publication No. 8099/1973 (JP=B1) and U.S. Pat. No. 4,558,059. N-thiazolyl oxamic acid derivatives are disclosed in J. Med. Chem. 26, 1158-1163(1983). N-tetrazolyl benzamides are disclosed in U.S. Pat. Nos. 4,526,979, 4,567,193 and 4,146,631, J. Med. Chem. 29, 538-549(1986) and ibid, 29, 2403-2409(1086). N-tetrazolyl nicotinamides are disclosed in J. Med. Chem. 26, 1499-1504(1983). Thiazolylmethyl tetrazoles are disclosed in Japanese Patent Publication (Unexamined) No. 167685/1986(JP=A).